The present invention relates generally to laryngeal airway devices. More particularly, the present invention relates to a laryngeal airway device that can be coupled to an introducer and guided into position in the throat.
The prior art is replete with devices and equipment for the management of a human airway in order to control respiration. For example, an airway device facilitates ventilation of the lungs of a person. The purpose of such a device is to provide an air pathway from an external air source, through the mouth, throat, and trachea, to the lungs. Additionally, some airway devices provide a seal with the throat of a person, which allows positive pressure ventilation and which may also prevent the leakage of stomach contents into the trachea (aspiration).
It is useful to divide airway devices into two categories: those that pass through the vocal chords and are commonly referred to as xe2x80x9ctracheal tubes,xe2x80x9d and those that lodge in the throat, above the vocal chords, and are commonly referred to as xe2x80x9cairways.xe2x80x9d As used herein, an xe2x80x9cairwayxe2x80x9d refers to a device that provides a fluid pathway from outside the mouth of a person to a location above the vocal chords.
In the variety of airway devices that are available, some merely support the tissue of the pharynx (throat), particularly the tongue, creating a passageway so that air can pass by and into the pharyngeal space toward the laryngeal opening, which is the opening into the voice box. Other airway devices include a tube that provides an air channel to a location near the laryngeal opening. Still other airway devices add a sealing means to the distal end of the tube in order to provide some degree of sealing between the tube and the natural airway of the person.
A laryngeal mask is an example of a sealing airway device. U.S. Pat. Nos. 4,509,514, 4,995,388, and 5,355,879 disclose laryngeal masks. A laryngeal mask includes an inflatable doughnut-shaped balloon which, when inflated, circles the laryngeal opening and creates a fluid seal between the outside of the inflated balloon and the tissues in the pharyngeal structures of the throat that surround the larynx.
The cross-referenced patent applications and issued patents (all assigned to the assignee of this application and incorporated in their entirety by this reference) disclose various airway devices, each including a sealing member mounted near the distal end of an airway tube to seal directly with the rim of the laryngeal opening, including the epiglottis, aryepiglottic folds, and arytenoid cartilages. This type of airway design creates a fluid seal directly with the larynx.
Accurate placement of an airway device can be a very difficult task for the clinician and a traumatic event for the patient. When a patient is under anesthesia, or has lost consciousness for other reasons, the tongue and tissues of the throat relax and fall back, effectively obstructing the flow air from the mouth or nose to the laryngeal opening. This same relaxation of the tongue makes it difficult to pass an airway device along the back of the tongue, into the throat. Frequently, the clinician""s fingers must be inserted into the patient""s mouth to displace the tongue or push the airway device around the corner at the posterior pharynx. Furthermore, the highly variable and extremely flexible anatomy surrounding the larynx make accurate positioning of an airway device very difficult. In particular, the epiglottis must be correctly positioned in order to introduce and seat an airway device that effectively seals against the laryngeal opening. An epiglottis that covers the larynx will prevent proper ventilation. Finally, the mucosal tissues lining the mouth, throat, and larynx are very fragile. Devices that are inserted blindly frequently scrape these tissues causing bleeding, sore throats, and throat infections.
A sealing laryngeal airway device forms a fluid seal against the rim of the laryngeal opening, that is, against the larynx itself. An airway device configured in accordance with the present invention includes features designed to enhance the seal against the laryngeal opening and to make insertion and alignment of the airway device easier for the clinician.
The above and other aspects of the present invention may be carried out in one form by a laryngeal airway device comprising an air tube having a first end and a second end, the air tube defining an airway, and a sealing member mounted to the air tube proximate the first end. The sealing member includes a support member having an anterior support surface, and a tubular extension protruding beyond the anterior support surface, the tubular extension further defining the airway, where the tubular extension terminates at a cupped lip.
The above and other aspects of the present invention may be carried out in another form by a laryngeal airway device comprising an air tube having a first end and a second end, and a sealing member mounted to the air tube proximate the first end. The sealing member includes a support member having an anterior support surface, a compressible pad, and an inflatable balloon positioned between the anterior support surface and the compressible pad.